1. Field of the Invention
The present invention relates to a touch sensing apparatus and a method thereof that can accurately determine a touch by setting different parameters for measuring variations in capacitance and determining the touch depending on a sensing electrode or a sensing channel.
2. Description of the Related Art
Touch sensing apparatuses such as a touch screen, a touch pad, and the like, as user interface apparatuses attached to a display apparatus to provide an intuitive input method to a user, have been widely applied to a variety of electronic apparatuses such as a cellular phone, a personal digital assistant (PDA), a navigation device and the like, in recent years. In particular, recently, with the increase in demand for smart phones, the rate at which a touch screen has been adopted as a touch sensing apparatus capable of providing various input methods in a limited form factor has increased on a daily basis.
Touch screens adopted in portable electronic apparatuses may be largely classified into resistive type and capacitive type touch screens, according to a touch sensing method. Since the capacitive type touch screen is advantageous in that a life-span thereof may be relatively extended, and various input methods and gestures can be easily implemented therein, the adoption rate of the capacitive type touch screen has steadily increased. In particular, it is easier to implement a multi-touch interface in the capacitive type touch screen than in the resistive type touch screen, and as a result, the capacitive type touch screen is widely applied to an electronic apparatus such as a smart phone, or the like.
The capacitive type touch screen includes a plurality of electrodes connected to a plurality of sensing channels and senses a touch from a variation in capacitance, generated by the touch, in each electrode. Accordingly, the distance between the position of an electrode, in which the variation in capacitance is to be detected, and the position of the sensing channel, influences a response speed in detecting the variation in capacitance. When the variation in capacitance is detected in an area relatively distant from the sensing channel, overall performance may be deteriorated due to a low response speed.